OF WASHINGTON. 79 



American insects, it might be well to continue to follow these 

 writers, but the time is passed when new species can be described 

 without reference to foreign literature, not only because many 

 species will be found to be common to the old and new worlds, 

 but others, especially those affecting cultivated plants once re 

 stricted to one or the other hemisphere, are being or will be by 

 the agency of commerce more and more widely distributed. 

 Comparisons with foreign descriptions will therefore, in the future, 

 have to be the rule, and it will be easier now than later to har 

 monize our characterizations with those of European writers. 

 This will not necessitate the introduction of a new and strange 

 terminology, for the accepted European systems are not, after all, 

 so widely divergent from Norton's, and will be found, with a few 

 important exceptions, to differ on account of additions rather than 

 changes. 



Of the later important European writers on the Tenthredinidae, 

 Cameron, Andre, and Konow, I have most closely followed the 

 first, introducing, in fact, few and unimportant changes and some 

 few additions of parts not designated by him. 



I have given preference to Cameron's system of nomenclature, 

 because I believe it to include the terminology most often used 

 and because his extensive monograph in English will be more fre 

 quently referred to by American students than Andre's, in which, 

 however, the system followed differs only in minor and, in gen 

 eral, unimportant particulars. Fora full synonymy of the termi 

 nology employed by all the older European writers, the excellent 

 lists furnished by Cameron and Andre may be referred to. The 

 system here adopted is illustrated, with explanations accompany 

 ing, in Fig. 2. 



The names of veins and cells in anterior and posterior wings 

 correspond, except that in the posterior wings the ist cubital (8) 

 is usually called the upper discal, the lower discal being num 

 bered (10) in the figure, and the cells numbered (n) and (12) 

 are the ist and 2d posteriors. 



The only important divergence from Cameron is the addition 

 of the terms axillary for nerve (_/") of the posterior wings which 

 also sometimes occurs as a rudiment in the anterior wing ; and 

 the designation of cell (2) as sub-costal rather than humeral. 



Andre's system differs only in the following particulars. Of 

 the veins: j is called posterior; /, transverse brachial ; p, mar- 

 gino-discoidal, and s and /, medio and transverse discoidals. Of 

 the cells, (i) is the brachial and (2) costal. 



In the system of Cresson and Norton, so far as the veins have 

 been designated, there are but two changes, viz., (7z) is the mar 

 ginal and (/) transverse marginal ; with the cells (2) is the median, 

 (3) sub-median, (6) marginal, (S-n) sub-marginal, and (15 and 

 16) apical. 



